CVE-2026-34890: Mark O’donnell Mstw League Manager

Medium severity, CVSS 6.5. EPSS: 0.2% chance of exploitation in the next 30 days.

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Mark O’Donnell MSTW League Manager allows DOM-Based XSS.This issue affects MSTW League Manager: from n/a through 2.10.

Affected products

• Mark O’donnell Mstw League Manager: up to and including 2.10

Published 2026-04-02. Last modified 2026-06-17.